Synchronizer



Afi 12, 1941.

w. BENZ SYNCHRONIZER Filed May 21, 1940 5 Sheets-Sheet 2 Fig.

Inventor Aug. 12, 1941.

W. BENZ SYNCHRONI ZER Filed May 21, 1940 Fig. 5

3 SheetS Sheet 3 Inventor:

Patented Aug. 12, 1941 SYNCHRONIZER Walter Benz, Leverkusen-Schlebusch, Germany,

assignor to Kliickner-Humboldt-Deutz Aktiengesellschaft, Cologne-Deutz, Germany, a corporation of Germany Application May 21, 1940, Serial No. 336,337

In Germany February 1'7, 1939 (c1. co-'97) 10 Claims.

The invention relates to a synchronizing device for power units, in which discrepancies between the angular movements of theshaft of one power unit and that of a pacemaker ma- According to Fig. 1 internal combustionengines l and 2 drive the screws of the ship through shafts 3 and 4, respectively. During cruising running of the ship the ship's screws are rechine-usually a similar power unit-are used 5 quired to run constantly at the same angular for varying the fuel supply to the synchronized velocity and, in order to reduce to the smallest power unit. value vibrations caused by them, to maintaina In many cases it is not sufficient that the rodefinite angular relation to each other, which tary speed of the synchronized power unit correcorresponds to this minimum value. In order to spends with that of the pacemaker, but it i adachieve this result one of the internal combusditionally necessary to maintain a definite antion engines, in this case the one designated 2, is gular relation of the shaft of the synchronized made the pacemaker. This pacemaker machine power unit and that of the pacemaker continucontrols the other internal combustion engine I, ously. The latter is desired, for example, in through the regulating device now to be explural screw ships power units in which each pla in Such Y that its Shaft 3 s screw is driven by a prime mover, because the actly the same rotary speed as the shaft 4 driven vibration of the ship produced by the propeller by the pacemaker machine 2, and retains a defiblades has been found to be a minimum with cernite angular position with respect to the latter; tain relative angular position of the screw selected with a view to reducing vibrations to a shafts. v minimum. a

In accordance with the invention two phase The regulating device consists essentially of indicators are provided showing the relative antwo phase indicators a and b. As phase indigular position of the shafts of the synchronized cators, planetary differential mechanisms may power unit and the pacemaker, which are conbe used, for example,..'the housings of which, 9 nected through a differential mechanism to the and III, are not held stationary a the g a s of fuel adjusting member of the synchronized power which are driven in opposite directions by means unit. One of the phase indicators controls the of the bevel gears H, l2 and l3, l4, by the pacefuel feed, in known manner, in dependence upon maker shaft 4 and the shaft 3 to be synchronized the rate and direction of discrepancies between in speed and angular relation to it. The housthe angular movements of the shafts of the synings 9, Ill, of the phase indicators serve as adchronized power unit and the pacemaker, while justingmembers for'the fuel feed of the mathe other imparts additional adjustments to the chine I in which is to be synchronized, because fuel feed, through a servo-motor, as long as the when the latter leads they turn in one direction instantaneous angular relation of the shafts is and when it lags behind they turn in the oppodifierent from one or more predetermined angusite direction. The adjustment of the fuel feed lar relations. i is accomplished through a difierential lever l5? The differential mechanism may compris a to the fulcrum of which the fuel-adjusting memdifferential lever, or, to give a greater range of her I6, for instance theregulating rod of the fuel adjustment, it may be a planetary gearing. pump I1, is connected, preferably through an In the drawings are shown several embodi- 40 inserted damping device l8. To one arm of the ments. of the invention; differential lever I5 is connected the adjusting Fig. 1 is a somewhat diagrammatic plan view member 9 of the phase indicator a. The rotary of a synchronizing device with two phase indimotion of the adjusting member 9 is limited by caters, for a ship's drive with two screws; stationary stops K (Fig. 2), in accordance with Fig. 2 is a vertical section on the line A--A of the extent of movement of the fuel control member IS. The phase indicator a therefore ad- Fig. 3 is a vertical section'on the line B-B of justs the fuel feed in accordance with the size i and direction of discrepancies between the angu- Fig. 4 is a diagrammatic plan view of another lar movements of the pacemaker 4 and the shaft embodiment of the invention; 3 to be synchronized. To the other arm of the Fig. 5 is a diagrammatic plan view of still andifferential lever I5 is connected 9. servo-motor other embodiment utilizing a single phase indi- IS, the controlling valve 20 of which is operated cator; and by the adjustingmember ill of the phase indi- Fig. 6 is a diagrammatic plan-view ofa slightly I .cator b, for example, by means of a cam 2| on modified form of the invention.

the adjusting member (see Fig. 3). The cam 2| is so arranged that at a given angular relation of shafts 3 and 4 which produces the minimum vibration the control valve 20 is held in it middle position, so that the servo-motor is out vof eration by means of the control valve 20 in the direction to increase the fuel feed, and is kept in operation until the angular deviation has been made up by the resulting increase in rotary speed of the shaft 3; while, when the shaft 3 leads the shaft 4, causing the adjusting member III to turn in "the opposite direction, the fuel feed is reduced until the angular deviation has been eliminated by the resulting reduction in the speed of the shaft 3. In place of the cam 2| a crank can also be provided on the adjusting member III, which holds the control valve in its neutral position at a certain setting and, according to the direction ofits departure from this setting, displaces the control valve in one direction or the other.

The regulating device is coupled and uncoupled by a friction clutch 22, which is so set that it slips as soon as the adjusting member 9 strikes against one of the abutments X. When the regulating device is cut out, an ordinary centrifugal governor 23 takes over the control of the speed of the motor I. For this purpose the setting rod 24 of the centrifugal governor engages the fuel setting member I 6. In order to provide an adjustment of the fuel feed without slack motion, the adjusting gear I5 and the phase indicator a are put under tension by a spring 45, which transmits its force through the differential transmitting mechanism I5 to the adjusting member 9.

Operation.Before throwing in the regulating device the machine I, which is to be synchronized, is brought up to a somewhat higher speed than the pacemaker machine 2, by compressing the.

governor spring of the centrifugal governor 3. Then simultaneously the clutch 22 and the pressure supply to the servo-motor I9 are thrown in. Since at this moment the shaft 3 is rotating faster than the shaft 4, the adjusting member 9 of the phase indicator a turns in counterclockwise direction (Fig. 2) and displaces the fuel control member I5, through the differential lever I5 and the damping device I8, in the direction to reduce the fuel feed. Thereby the speed of the machine I is immediately reduced and approaches that of the pacemaker machine 2. The speed regulator 23, adjusted to a higher speed, lowers its setting rod 24 from the fuel setting member IS and thereby'cuts itself out of the regulating process. As soon asthe rotary speed of the machines I and 2 becomes identical, the reduction of the fuel feed is stopped by the return to rest of the adjusting member 9 of the phase indicator 11. Now if the shafts 3 and 4 do not hold the definite angular relation to each other which produces the minimum vibration, but require, for instance, an additional forward movement of the shaft 3 through a certain angle, in order for it to assume the predetermined angular relation with respect to the pacemaker shaft 4, the setting member III of the phase indicator 2: assumes such a position that the cam 2I keeps the servo-motor I9 in operation in the direction to increase the fuel feed. This has the result that the machine I increases its speed over that of the pacemaker machine 2 and takes up the angular difference. I

Meanwhile, however, the adjusting members 9 and III of the phase indicatorsa and bturn. The adjusting member I0 turns the .cam 2I toward the neutral position which stops the servo-motor I9 .and which corresponds to the predetermined angular relation of the shafts 3 and 4, while the phase indicator a restores the increase in the fuel feed caused by the phase indicator b through the differential lever I5. As soon as the neutral position of the cam 2I is reached, the regulating procedure is finished. The machines I and 2 then run at the same speed and the shafts 3 and 4 are at the predetermined angular relation which produces the minimum vibration. Naturally the two regulating procedures do not take place successively as described, but simultaneously. The damping device I8 has the function of preventing oscillations during the regulation.

When a plurality of definite angular relations of shafts 3 and 4 produce a minimum vibration, a number of cam lobes corresponding to the number of these angular positions can be provided on the adjusting member ID of the phase indicator b.

In order to reduce to the minimum, vibrations caused by the motors themselves, the couplings (not shown) between the crank shafts of the motors and the ships screw shafts 3 and 4 are so arranged that not only the'crank shafts of the motors I, 2, but also the screws produce a minimum vibration at a predetermined relative angular position. The cam 2| on the adjusting member ID of the phase indicator is then so ar-, ranged that it holds the control valve 20 in its neutral position at this preferred relative angular position. If as indicated in dot and dash lines in Fig. 1, there are inserted driving gears 5, 6, between the ships screws and the motors I, 2in the present example between the Voith-Schneider propellers 'I, 8'f'and the motors 2their driving ratio must naturally be taken into consideration. If it is assumed, for instance, that thedriving ratio between the motors and the screws is 3:1 and that there is a most favorable relative angular position of the screws and also of the motor shafts, then the most favorable relative angular position of the screws corresponds to that of the motor shafts at intervals of three revolutions of one motor in excess of the other. Since the regulating device, in order to be as sensitive as possible, is preferably connected to the high speed side of the power plant, the most favorable angular relation of the shafts occurs at intervals of three rotations of the adjusting member III or cam 2| on the phase indicator b, if the transmission ratio of the gears I3, I4, of the phase indicator b is 1:2. Furthermore,'it has to be considered that in order to provide a uniform wear of the teeth of the driving gears, one wheel should be made with one tooth more or less than it re- For example, if

quires for a simple driving ratio. for producing a transmission ratio 1:3 the small wheel has 45 teeth and the large one, instead of 135, has only 134 teeth, then 134.3:402 revolutions of the adjusting member I0 are required before the preferred angle will be repeated. A gear transmission in the power line consequently has the result, that the regulating device only establishes and maintains the preferred angular position if it is thrown in exactly at that rotation of the adjusting member I II when the most favorpointer 28 is so operated by a gear drive 26, that it executes one revolution while the adjusting tions of the motor shaft and screws, the indicating device either has a corresponding number of stationary marks, or is driven at a smaller 'ratio corresponding to the number of preferred relative angular positions, so that thepointer 28 i executes one complete revolution between each of these relative angular positions.

The differential lever l5 can be replaced by a planetary gearing 29, as shown in Fig. 4. The differential mechanism 29 is inserted in the line of shaft 30 of the phase indicator (1. and the housing 3| of the latter is turned in one direction or another by servo-motor l9 through gear 32, according to the position of cam 2|. IYhe rotation of the housing 3| is transmitted through the gears of the differential mechanism 29 and of the phase indicator a to the adjusting member 9 of the latter and from there through the damping device l8 to the fuel pump II. The turning of adjusting member 9 caused by differences in rotary speed of shafts 3 and 4 is added to that speed of shaft 3 required for producing synchronism and that required for producing the preferred relative angular position must take place in opposite directions. The rotary motion of adjusting member 9 is so'limited, in the same manner as shown in Fig. 2, that it-can make no This cam, according to the direction of deviation from the predetermined relative angular position of the shafts, causes a forward or backward turning of the servo-motor and holds this until the shafts 3 and 4 have again assumed the predetermined relative angular position. The servomotor 4| turns the housing 43 of differential mechanism 34 through the gear 42 and thereby brings about an additional adjustment of the fuel pump 39, acting through the wheels 33, the friction clutch 35, the cable drive 36, and the damping device 31. This additional adjustment is either added to or subtracted from that caused by the adjusting member 52, according to whether the change in rotary speed of shaft 3 for the purpose of producing synchronism must take place in the same direction or in the opposite direction to that required for restoring the shafts 3 and to the predetermined relative phase indicator,.in order to eliminate slack in the j gears.

greater movement than that required for a maximum adjustment of the fuel setting member. The spring serves for pre-tensioning the phase indicator a, in order to eliminate play in the gears. The power plant shown in Fig. 4 corresponds in other respects in construction and manner of operation with that shown in Fig. 1.

In Fig. 5 is shown a regulating device which has, instead -of two phase indicators, only one. The phase indicator 0 is again a planetary gearing, the wheels of which are driven through gears 50, 5|, in opposite directions by the shafts 3 and 4 of the machine to be synchronized and the pacemaker. The housing 52 is the adjusting member of the phase indicator. It is connected to the adjusting member of the fuel pump 38 through wheels 33 of a differential mechanism 34, friction clutch 35, cable drive 36, and a damping device 31. Thereby it controls directly the-fuel feed in dependence upon the size and direction of discrepancies between the angular movements of the synchronized shaft 3 and the pacemaker shaft 4. In addition, the adjusting member 52 has a cam 39, which holds the control valve 40 of servo-motor 4| in the neutral'positon, exactly like cam 2| in Figs. 1 and 4, when the shafts 3 and4 have a predetermined relative angular position, which produces the minimum 'vibration.

angular position. The adjusting member 52 therefore takes over directly and simultaneously the functions of the phase indicators b of the em bodiments shown in Figs. 1 and 4.

' In place of the differential mechanism 34 there can naturally be used a differential lever 53 as shown in Fig. 6, like the differential lever I5 of' Fig. 1. The adjusting member 52 of the phase indicator .0 is then connected through a friction clutch 35 and cable drive 36 to one end of the differential lever 53; while the servo-motor 4|, in the form of a reciprocating motor, is connected to the other end of the. differential lever. The indicating device is driven by the adjusting member 52, as in the embodiment shown in Fig. 1. The spring 45 again serves to pre-tension the a The synchronizing device is naturally not limited to ship's drives, but is suitable for all power plants in whichseparately driven shafts must.

be held continuously at the same rotary speed and at one or more predetermined angular positions with respect to each other.

I claim: I

1. In a device for synchronizing shafts driven by'separate prime movers at least one of which has a speed-changing device, means geared to both said shafts comprising an actuating member movable in de endency upon the size and direction of any discrepancies between the angular movements of said shafts, means geared to bo h said shafts comprising an actuating member' -movab1e in accordance with the direction of any deviations of the instantaneous relative angular positions of said shafts from one or more predetermined relative'angular positions. means for compounding themovements of said actuating members, and means for transmitting the compounded movement to said speed-changing device. I

2. In a device for synchronizing shafts driven by separate prime movers at least one of which has a speed-changing device, means geared to both-said shafts comprising an actuating member movable in dependency upon the size and direction of any discrepancies between the angular movements of said shafts, means geared to both said shafts comprising an actuating member movab e in accordance with the direction of any deviations of the instantaneous relative angular positions of said shafts from. one or more predetermined relative angular positions. a servomotor having a control member operated by said second actuating. member, means for compounding the movement of said servo-motor with the positions.

movement of said first actuating means, and

, means for transmitting the compounded movement to said speed-changing device.

3. In a device for synchronizing shafts driven by separate prime movers at least one of which has a speed-changing device, a differential mechanism connected to said speed-changing device, two phase indicators each geared to both of said shafts and operatively connected with said differential mechanism, one of said phase indicators being adapted to adjust said speed-changing device through said diiferential mechanism in dependency upon the size and direction of any discrepancy between the angular movements of said shafts, the other of said phase indicators being adapted to adjust said speed-changing device through said differential mechanism in dependency upon the direction of any deviation of the instantaneous relative angular position of said shafts from one or more predetermined angular 4; In a device for synchronizing shafts driven by separate prime movers at least one of which has a speed-changing device,-a differential mechnism connected to said speed-changing device, a phase indicator geared to both of said shafts and operatively connected with said differential mechanism, said phase indicator being adapted to adjust said speed-changing device through said differential mechanism in dependency upon the by separate prime movers at least one of which has a speed-changing device, a differential mechanism, operative connections between said differential mechanism and said speed-changing device,'a phase indicator geared to both of said shafts, and two parallel lines of connections between said phase indicator and different parts of said differential mechanism, one of said lines of connections being adapted to transmit adjustments from said phase indicator to said speedchanging device in dependency upon the size and direction of any discrepancy between the angular movements of said shafts, the other line of connections including a servo-motor adapted to impart a secondary adjustment to said speedchanging device so long as there is any deviation of the instantaneous relative angular position of said shafts from one or more predetermined relative angular positions.

'7. In a device for synchronizing shafts driven by separate prime moversat least one of which has a speed-changing device, means geared to both said shafts comprising an actuating member movable in dependency upon the size and direction of any discrepancies between the angular movements of said shafts, a phase indicator geared to both said shafts including a cam movable in opposite directions in accordance with the size and direction of any discrepancy between the angular movements of said shafts, a servo-motor connected to said differential mechanism and having a control member, a second phase indicator geared to both said shafts comprising an actuating member movable in accordance with the direction of any deviation ofv the instantaneous relative angular position of said shafts from one or more predetermined relative angular positions, said actuating member being adapted to operate said servo-motor control member and thereby, through said differential mechanism, to impart a secondary adjustment to said speedresponsive device until, by suitable modification the speed of the prime mover having said speedchanging device, said shafts are restored to one of said predetermined relative angular positions and said servo-motor control member isretumed to neutral position.

5. In a device for synchronizing shafts driven by separate prime movers at least one of which has a speed-changing device, two phase indicators each having driving means geared to both said shafts, a planetary differential mechanism" inserted in the driving connections of one of said adapted, independently of said differential mec h-- anism to adjust said speed-changing device in dependency upon the size and direction of any discrepancy between the angular movements of said shafts said second phase indicator being adapted to control said servo-motor to impart a secondary adjustment to said speed-changing device, through said differential mechanism and said first phase indicator, so long as there is any deviation of the instantaneous relative angular relative angular position of said shafts from one or more predetermined relative angular positions, a servo-motor having a control member and actuating means therefor including a follower coacting with said cam, means for compounding the movement of said servo-motor with the movement of said first actuating member, and means fortransmitting the compounded movement to said speed-changing device, said cam and the actuating means coacting therewith being adapted to hold said servo-motor control member in neutral position when said shafts are in one of said predetermined relative angular positions and said cam being so shaped that when turned in the direction corresponding to a lagging deviation of the shaft driven by the prime mover having said speed-changing device, it moves said control member to position to operate said servo motor in the direction which will advance said speed-- changing device, while a turning of said cam resulting from a leading of the shaft driven by the prime mover having said speed-changing device moves said control member to position to operate said servo-motor in the direction which will retard said speed-changing device.

8. A device as described in claim 1, wherein means are provided to limit the movement of said transmitting means in conformance with the range of movement of said speed-changing device, and a friction clutch is inserted in the line of mechanism connecting said shafts with said speed-changing device through said means comprising said first-actuating device.

9. In a device for synchronizing power units each comprising a drive shaft operated by a separate prime mover, a driven shaft, and gearing connecting said shafts to run at different speeds, at least one of the prime movers having a speedchanging device; a phase indicator geared to corresponding shafts of both power units including an actuating member movable in accordance with the direction of any deviations of the instantaneous relative angular positions of said shafts from one or more predetermined relative angular positions; means controlled by said actuating from a given instantaneous angular position relative to the shafts to which they are connected by said gearing, back to the same relative angular position.

10. A device asdescribed in claim 1, wherein a spring is provided to urge said transmitting means in one direction, in order to take up play.

WALTER BENZ. 

